1. Field of the Invention
The present invention relates to machining tools for performing turning (lathe) and gear cutting operations on a workpiece.
2. Description of the Related Art
Japanese Laid-Open Patent Publication No. 11-197901 discloses a gear cutting device that is mounted on a turret of a numerically controlled lathe. Japanese Laid-Open Patent Publication No. 56-56337 discloses a gear cutting device that is provided separately from the turret. These machine tools are capable of performing a turning operation by using a turning tool attached to the turret and a gear cutting operation by using a gear cutting tool attached to the gear cutting device.
However, in the former complex machining tool, the drive mechanisms of the turning device and the gear cutting device are incorporated in the turret. Therefore, the construction is complicated and the turret is large in size. In the latter complex machining tool, the turning device and the gear cutting device are separately constructed, which increases the number of parts and thus the manufacturing cost of the machine tool.
It is, accordingly, one object of the present teachings to reduce the number of parts and thus the cost and size of complex machining tools that have a turning device (e.g., a lathe tool) and a gear cutting device (e.g., a hob). For example, the turning device and the gear cutting device may commonly utilize components in order to reduce the number of parts necessary to construct and operate the machining tool.
In one aspect of the present teachings, complex machining tools include a turning device and a gear cutting device. Preferably, the turning device and the gear cutting device are mounted on a single carriage. The carriage can move in a direction generally parallel to a rotational or longitudinal axis of a workpiece mounted between a headstock and a tailstock. By providing a single carriage on which both the turning device and the gear cutting device are mounted, components necessary to move the turning device and the gear cutting device in the direction generally parallel to the rotational or longitudinal axis of the workpiece can be commonly used. As a result, complex machining tools are taught that are capable of performing turning and gear cutting operations using a single carriage, which can substantially reduce the number of parts and thus can be manufactured at a reduced cost.
In another aspect of the present teachings, the turning device and the gear cutting device are arranged and constructed such that each can be moved independently on the carriage in a direction generally perpendicular to the rotational or longitudinal axis of the workpiece. As a result, when one of the turning device and the gear cutting device is used for machining the workpiece, the other device can be withdrawn to a position that will prevent interference with the device that is machining the workpiece.
In another aspect of the present teachings, machining methods are taught in which the turning device and the gear cutting device are mounted on a single carriage that can move in a direction generally parallel to the rotational or longitudinal axis of the workpiece. Accordingly, when a workpiece is machined using one of the turning device and the gear cutting device, the other (not used) device is moved to a position remote from the workpiece. For example, the turning device and the gear cutting device can be moved in a direction generally perpendicular to the rotational or longitudinal axis of workpiece.
Additional objects, features and advantages of the present invention will be readily understood after reading the following detailed description together with the accompanying drawings and the claims.